i.V?/.] FROGHOPPEB BLIGHT TX TRINIDAD. 65 



affccf the height of a brood. Neglect of this will render the operation 

 valueless. Trials have shown that there is little if any chance of 

 the survival of eggs in trash carried to the pens and distributed as pen 

 manure some months later. 



Weeding has a similar but less important effect and to be of any use 

 must be done at the same period. 



Burning destroys a certain proportion of the eggs of the froghopper, 

 but also n)any of its enemies and much good vegetable matter which 

 would have formed Inimus. As little burning as possible should be 

 carried out. 



Spraying has been recommended but is not practicable. 



The nymphs may be reduced by weeding and in some countries, but 

 not in Trinid.id, by iiooding the land. 



Fpraying for nymphs has been recommended, but no reliable cheap 

 lipiid has yet been discovered. The cost of the method, even with a 

 cheap spray, and the labour required to distribute it are much against 

 its general adoption. 



The nymphs can be crushed in their froth or hand collected by gangs 

 of children, bat both methods are expensive and only possible on a small 

 scale. 



The aditJt frofjhoppcrs are sometimes collected by hand, but this is 

 laborious. 



Spraying with kerosene emulsion has bsen recommended by Gough, 

 but no field trials have ever been made. 



Light traps catch large numbers of adults, but only about 1 per 

 cent, of these are females. Bright lamps are but little more attractive 

 than oil lamps, and green and red lights are found to attract fewer 

 adults than white, and no greater percentage of females. Lights 

 near the ground are more successful than if placed two to four feet up. 

 Other insects are destroyed by the lamps, but on the whole more are 

 injurious than useful. The liglit traps may be used for the spread of tho 

 green muscardine fungus, but the method suffers from the limitationg 

 due to the effect of weather on the spreaJ of infection. 



The adult froghoppers can b3 ciught in very large numbers by the 

 use of nets in the late evening and early morning when the adults are 

 sitting on the grass anl cane leaves. Ne'.s have been designed drawn 

 by mules in order to cover the ground rapidly in the limited time 

 available. Experiments are being continued on this line. 



Natural Enemies can be encouraged to a limited extent by providing 

 trees for birds to nest in, and by stopping all unnecessary burning. At 

 the same time the froghopper is a native insect and its enemies arc 

 probably on the average as efficient as thej' are ever likely to be. 



If the search for new enemies in other countries is again carried out 

 it must be recollected that it is a long and uncertain process. New 

 enemies are more likely to be found outside Central America, and Africa 

 is suggested as a likely pl.ice. At least two men should be engaged in 

 such a search, as results WiU be obtahied sooner and there is less likeli- 

 hood of failure. 



Several possible types of new enemies are indicated. 



